Modulation of central synapse remodeling after remote peripheral injuries by the CCL2-CCR2 axis and microglia.

Microglia-mediated synaptic plasticity after CNS injury varies depending on injury severity, but the mechanisms that adjust synaptic plasticity according to injury differences are largely unknown. This study investigates differential actions of microglia on essential spinal motor synaptic circuits following different kinds of nerve injuries. Following nerve transection, microglia and C-C chemokine receptor type 2 signaling permanently remove Ia axons and synapses from the ventral horn, degrading proprioceptive feedback during motor actions and abolishing stretch reflexes. However, Ia synapses and reflexes recover after milder injuries (nerve crush). These different outcomes are related to the length of microglia activation, being longer after nerve cuts, with slower motor-axon regeneration and extended expression of colony-stimulating factor type 1 in injured motoneurons. Prolonged microglia activation induces CCL2 expression, and Ia synapses recover after ccl2 is deleted from microglia. Thus, microglia Ia synapse removal requires the induction of specific microglia phenotypes modulated by nerve regeneration efficiencies. However, synapse preservation was not sufficient to restore the stretch-reflex function.

IOA-244 is a Non-ATP-competitive, Highly Selective, Tolerable PI3K Delta Inhibitor That Targets Solid Tumors and Breaks Immune Tolerance.

PI3K delta (PI3Kδ) inhibitors are used to treat lymphomas but safety concerns and limited target selectivity curbed their clinical usefulness. PI3Kδ inhibition in solid tumors has recently emerged as a potential novel anticancer therapy through the modulation of T-cell responses and direct antitumor activity. Here we report the exploration of IOA-244/MSC2360844, a first-in-class non-ATP-competitive PI3Kδ inhibitor, for the treatment of solid tumors. We confirm IOA-244's selectivity as tested against a large set of kinases, enzymes, and receptors. IOA-244 inhibits the in vitro growth of lymphoma cells and its activity correlates with the expression levels of PIK3CD, suggesting cancer cell-intrinsic effects of IOA-244. Importantly, IOA-244 inhibits regulatory T cell proliferation while having limited antiproliferative effects on conventional CD4+ T cells and no effect on CD8+ T cells. Instead, treatment of CD8 T cells with IOA-244 during activation, favors the differentiation of memory-like, long-lived CD8, known to have increased antitumor capacity. These data highlight immune-modulatory properties that can be exploited in solid tumors. In CT26 colorectal and Lewis lung carcinoma lung cancer models, IOA-244 sensitized the tumors to anti-PD-1 (programmed cell death protein 1) treatment, with similar activity in the Pan-02 pancreatic and A20 lymphoma syngeneic mouse models. IOA-244 reshaped the balance of tumor-infiltrating cells, favoring infiltration of CD8 and natural killer cells, while decreasing suppressive immune cells. IOA-244 presented no detectable safety concerns in animal studies and is currently in clinical phase Ib/II investigation in solid and hematologic tumors. Significance: IOA-244 is a first-in-class non-ATP-competitive, PI3Kδ inhibitor with direct antitumor in vitro activity correlated with PI3Kδ expression. The ability to modulate T cells, in vivo antitumor activity in various models with limited toxicity in animal studies provides the rationale for the ongoing trials in patients with solid tumors and hematologic cancers.

NHR-23 and SPE-44 regulate distinct sets of genes during Caenorhabditis elegans spermatogenesis.

Spermatogenesis is the process through which mature male gametes are formed and is necessary for the transmission of genetic information. While much work has established how sperm fate is promoted and maintained, less is known about how the sperm morphogenesis program is executed. We previously identified a novel role for the nuclear hormone receptor transcription factor, NHR-23, in promoting Caenorhabditis elegans spermatogenesis. The depletion of NHR-23 along with SPE-44, another transcription factor that promotes spermatogenesis, caused additive phenotypes. Through RNA-seq, we determined that NHR-23 and SPE-44 regulate distinct sets of genes. The depletion of both NHR-23 and SPE-44 produced yet another set of differentially regulated genes. NHR-23-regulated genes are enriched in phosphatases, consistent with the switch from genome quiescence to post-translational regulation in spermatids. In the parasitic nematode Ascaris suum, MFP1 and MFP2 control the polymerization of Major Sperm Protein, the molecule that drives sperm motility and serves as a signal to promote ovulation. NHR-23 and SPE-44 regulate several MFP2 paralogs, and NHR-23 depletion from the male germline caused defective localization of MSD/MFP1 and NSPH-2/MFP2. Although NHR-23 and SPE-44 do not transcriptionally regulate the casein kinase gene spe-6, a key regulator of sperm development, SPE-6 protein is lost following NHR-23+SPE-44 depletion. Together, these experiments provide the first mechanistic insight into how NHR-23 promotes spermatogenesis and an entry point to understanding the synthetic genetic interaction between nhr-23 and spe-44.

The Role of Microglia in Neuroinflammation of the Spinal Cord after Peripheral Nerve Injury.

Peripheral nerve injuries induce a pronounced immune reaction within the spinal cord, largely governed by microglia activation in both the dorsal and ventral horns. The mechanisms of activation and response of microglia are diverse depending on the location within the spinal cord, type, severity, and proximity of injury, as well as the age and species of the organism. Thanks to recent advancements in neuro-immune research techniques, such as single-cell transcriptomics, novel genetic mouse models, and live imaging, a vast amount of literature has come to light regarding the mechanisms of microglial activation and alluding to the function of microgliosis around injured motoneurons and sensory afferents. Herein, we provide a comparative analysis of the dorsal and ventral horns in relation to mechanisms of microglia activation (CSF1, DAP12, CCR2, Fractalkine signaling, Toll-like receptors, and purinergic signaling), and functionality in neuroprotection, degeneration, regeneration, synaptic plasticity, and spinal circuit reorganization following peripheral nerve injury. This review aims to shed new light on unsettled controversies regarding the diversity of spinal microglial-neuronal interactions following injury.

Sublethal effects of parasitism on ruminants can have cascading consequences for ecosystems.

Parasitic infections are common, but how they shape ecosystem-level processes is understudied. Using a mathematical model and meta-analysis, we explored the potential for helminth parasites to trigger trophic cascades through lethal and sublethal effects imposed on herbivorous ruminant hosts after infection. First, using the model, we linked negative effects of parasitic infection on host survival, fecundity, and feeding rate to host and producer biomass. Our model, parameterized with data from a well-documented producer­caribou­helminth system, reveals that even moderate impacts of parasites on host survival, fecundity, or feeding rate can have cascading effects on ruminant host and producer biomass. Second, using meta-analysis, we investigated the links between helminth infections and traits of free-living ruminant hosts in nature. We found that helminth infections tend to exert negative but sublethal effects on ruminant hosts. Specifically, infection significantly reduces host feeding rates, body mass, and body condition but has weak and highly variable effects on survival and fecundity. Together, these findings suggest that while helminth parasites can trigger trophic cascades through multiple mechanisms, overlooked sublethal effects on nonreproductive traits likely dominate their impacts on ecosystems. In particular, by reducing ruminant herbivory, pervasive helminth infections may contribute to a greener world.

Rational development and evaluation of novel formulations for urinary health.

OBJECTIVE: Urinary tract infections (UTI) among women form a substantial part of medical practice and both patients and medical professionals have an interest in non-antibiotic treatments and preventative measures. This research provides preliminary data on a multi-functional composition, DAPAD, which explored several biologic activities of relevance to UTI. STUDY DESIGN: This formulation included D-mannose, citric acid, three prebiotic compounds, and extracts of dandelion and astragalus. Studies performed employed 4 bacterial strains that have relevance to UTI including E. coli, Proteus mirabilis, Streptococcus agalactiae and Enterococcus faecalis. RESULTS: Key findings from in vitro studies included: DAPAD at full- and half-strength inhibited growth of all UTI bacteria. Evidence for D-mannose agglutination of E. coli was demonstrated. D-mannose also showed unexpected effects on bacterial membrane integrity with vital staining and modest growth restriction. We did not demonstrate growth inhibition by dandelion or astragalus extracts but the latter showed diminished cytokine elaboration by bladder epithelial cells. CONCLUSION: DAPAD is a multifunctional composition that may warrant further development as a UTI treatment or preventive if supported by clinical evaluation.

Autotaxin impedes anti-tumor immunity by suppressing chemotaxis and tumor infiltration of CD8+ T cells.

Autotaxin (ATX; ENPP2) produces lysophosphatidic acid (LPA) that regulates multiple biological functions via cognate G protein-coupled receptors LPAR1-6. ATX/LPA promotes tumor cell migration and metastasis via LPAR1 and T cell motility via LPAR2, yet its actions in the tumor immune microenvironment remain unclear. Here, we show that ATX secreted by melanoma cells is chemorepulsive for tumor-infiltrating lymphocytes (TILs) and circulating CD8+ T cells ex vivo, with ATX functioning as an LPA-producing chaperone. Mechanistically, T cell repulsion predominantly involves Gα12/13-coupled LPAR6. Upon anti-cancer vaccination of tumor-bearing mice, ATX does not affect the induction of systemic T cell responses but, importantly, suppresses tumor infiltration of cytotoxic CD8+ T cells and thereby impairs tumor regression. Moreover, single-cell data from melanoma tumors are consistent with intratumoral ATX acting as a T cell repellent. These findings highlight an unexpected role for the pro-metastatic ATX-LPAR axis in suppressing CD8+ T cell infiltration to impede anti-tumor immunity, suggesting new therapeutic opportunities.

Mesenchymal stem cells and three-dimensional-osteoconductive scaffold regenerate calvarial bone in critical size defects in swine.

Craniofacial bones protect vital organs, perform important physiological functions, and shape facial identity. Critical-size defects (CSDs) in calvarial bones, which will not heal spontaneously, are caused by trauma, congenital defects, or tumor resections. They pose a great challenge for patients and physicians, and significantly compromise quality of life. Currently, calvarial CSDs are treated either by allogenic or autologous grafts, metal or other synthetic plates that are associated with considerable complications. While previous studies have explored tissue regeneration for calvarial defects, most have been done in small animal models with limited translational value. Here we define a swine calvarial CSD model and show a novel approach to regenerate high-quality bone in these defects by combining mesenchymal stem cells (MSCs) with a three-dimensional (3D)-printed osteoconductive HA/TCP scaffold. Specifically, we have compared the performance of dental pulp neural crest MSCs (DPNCCs) to bone marrow aspirate (BMA) combined with a 3D-printed HA/TCP scaffold to regenerate bone in a calvarial CSD (>7.0 cm2 ). Both DPNCCs and BMA loaded onto the 3D-printed osteoconductive scaffold support the regeneration of calvarial bone with density, compression strength, and trabecular structures similar to native bone. Our study demonstrates a novel application of an original scaffold design combined with DPNCCs or BMA to support regeneration of high-quality bone in a newly defined and clinically relevant swine calvarial CSD model. This discovery may have important impact on bone regeneration beyond the craniofacial region and will ultimately benefit patients who suffer from debilitating CSDs.

Prevalence of HIV, HCV and HBV in Central Asia and the Caucasus: A systematic review.

BACKGROUND: Human immunodeficiency virus (HIV), hepatitis C virus (HCV) and hepatitis B virus (HBV) are substantial public health threats in the region of Central Asia and the Caucasus, where the prevalence of these infections is currently rising. METHODS: A systematic review of MEDLINE, Embase and PsycINFO was conducted with no publication date or language restrictions through October 2019. Additional data were also harvested from national surveillance reports, references found in discovered sources, and other "grey" literature. It included studies conducted on high-risk populations (people who inject drugs (PWID), female sex workers (FSW), men who have sex with men (MSM), prisoners, and migrants) in Central Asia: Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan, and Uzbekistan; and the Caucasus: Armenia, Azerbaijan, Georgia, and Northern Caucasus region of the Russian Federation. RESULTS: Wide ranges were noted for HIV prevalence: PWID 0-30.1%, MSM 0-25.1%, prisoners 0-22.8%, FSW 0-10.0%, and migrants 0.06-1.5%, with the highest prevalence of these high-risk groups reported in Kazakhstan (for PWID), Georgia (for MSM and prisoners) and Uzbekistan (for migrants). HCV prevalence also had a wide range: PWID 0.3-92.1%, MSM 0-18.9%, prisoners 23.8-49.7%, FSW 3.3-17.8%, and migrants 0.5-26.5%, with the highest prevalence reported in Georgia (92.1%), Kyrgyzstan (49.7%), and migrants from Tajikistan and Uzbekistan (26.5%). Similarly, HBV prevalence had a wide range: PWID 2.8-79.7%, MSM 0-22.2%, prisoners 2.7-6.2%, FSW 18.4% (one study), and migrants 0.3-15.7%. CONCLUSION: In Central Asia and the Caucasus, prevalence of HIV, HCV and HBV remains exceedingly high among selected populations, notably PWID and MSM.

Infectious Diseases, Livestock, and Climate: A Vicious Cycle?

Ruminant livestock are a significant contributor to global methane emissions. Infectious diseases have the potential to exacerbate these contributions by elevating methane outputs associated with animal production. With the increasing spread of many infectious diseases, the emergence of a vicious climate-livestock-disease cycle is a looming threat.

Acute Chemical Eye Injury and Limbal Stem Cell Deficiency-A Prospective Study in the United Kingdom.

PURPOSE: To analyze the incidence, nature, outcomes, and complications of acute chemical eye injuries, including the incidence of limbal stem cell deficiency (LSCD) and to compare the 2 main classifications for ocular chemical injuries: Roper-Hall (RH) and Dua. METHODS: This is a prospective, consecutive, interventional single-center study between April and October 2009 of all new patients with acute chemical eye injury presenting to the Royal Victoria Infirmary eye emergency department (EED). RESULTS: Of 11,683 patients who attended the EED, 98 patients (110 eyes) presented with acute chemical eye injury (60% male). This represents an estimated annual incidence of 5.6 new cases per 100,000 population. Mean age was 36.5 years (1-78; SD 17.1 years), including 7 children (age <10 years). Fifty-one patients (52%) had work-related injuries. The most common chemical agent was alkali (78%). All 4 RH grade IV cases were unilateral, assault with ammonia, and required early amniotic membrane transplantation as per the protocol, but despite full treatment, they developed total LSCD in the affected eye. CONCLUSIONS: Acute chemical eye injuries are rare. Male patients in the working age group are more prone to work-related chemical injuries, whereas young children tend to have domestic injuries. Grade I, II, and III RH and Dua chemical injuries had a very good prognosis with topical treatment only, whereas RH grade IV (Dua grade IV-VI), mainly assaults with ammonia, progressed to total/severe LSCD despite appropriate management including early amniotic membrane transplantation. The Dua classification includes conjunctival involvement, having a greater value in predicting the final clinical outcome when grading chemical eye injuries.

Preclinical Development of a Bispecific Antibody that Safely and Effectively Targets CD19 and CD47 for the Treatment of B-Cell Lymphoma and Leukemia.

CD47, an ubiquitously expressed innate immune checkpoint receptor that serves as a universal "don't eat me" signal of phagocytosis, is often upregulated by hematologic and solid cancers to evade immune surveillance. Development of CD47-targeted modalities is hindered by the ubiquitous expression of the target, often leading to rapid drug elimination and hemotoxicity including anemia. To overcome such liabilities, we have developed a fully human bispecific antibody, NI-1701, designed to coengage CD47 and CD19 selectively on B cells. NI-1701 demonstrates favorable elimination kinetics with no deleterious effects seen on hematologic parameters following single or multiple administrations to nonhuman primates. Potent in vitro and in vivo activity is induced by NI-1701 to kill cancer cells across a plethora of B-cell malignancies and control tumor growth in xenograft mouse models. The mechanism affording maximal tumor growth inhibition by NI-1701 is dependent on the coengagement of CD47/CD19 on B cells inducing potent antibody-dependent cellular phagocytosis of the targeted cells. NI-1701-induced control of tumor growth in immunodeficient NOD/SCID mice was more effective than that achieved with the anti-CD20 targeted antibody, rituximab. Interestingly, a synergistic effect was seen when tumor-implanted mice were coadministered NI-1701 and rituximab leading to significantly improved tumor growth inhibition and regression in some animals. We describe herein, a novel bispecific antibody approach aimed at sensitizing B cells to become more readily phagocytosed and eliminated thus offering an alternative or adjunct therapeutic option to patients with B-cell malignancies refractory/resistant to anti-CD20-targeted therapy. Mol Cancer Ther; 17(8); 1739-51. ©2018 AACR.

Glycosaminoglycan Interactions with Chemokines Add Complexity to a Complex System.

Chemokines have two types of interactions that function cooperatively to control cell migration. Chemokine receptors on migrating cells integrate signals initiated upon chemokine binding to promote cell movement. Interactions with glycosaminoglycans (GAGs) localize chemokines on and near cell surfaces and the extracellular matrix to provide direction to the cell movement. The matrix of interacting chemokine-receptor partners has been known for some time, precise signaling and trafficking properties of many chemokine-receptor pairs have been characterized, and recent structural information has revealed atomic level detail on chemokine-receptor recognition and activation. However, precise knowledge of the interactions of chemokines with GAGs has lagged far behind such that a single paradigm of GAG presentation on surfaces is generally applied to all chemokines. This review summarizes accumulating evidence which suggests that there is a great deal of diversity and specificity in these interactions, that GAG interactions help fine-tune the function of chemokines, and that GAGs have other roles in chemokine biology beyond localization and surface presentation. This suggests that chemokine-GAG interactions add complexity to the already complex functions of the receptors and ligands.

Antibody Neutralization of CXCL10 in Vivo Is Dependent on Binding to Free and Not Endothelial-bound Chemokine: IMPLICATIONS FOR THE DESIGN OF A NEW GENERATION OF ANTI-CHEMOKINE THERAPEUTIC ANTIBODIES.

To improve our understanding of properties that confer successful inhibition of chemokines in vivo, we analyzed anti-murine CXCL10 monoclonal antibodies (mAb) having different characteristics. 1B6 displayed potent inhibition of cell recruitment in vitro with an IC50 of 0.5 nm but demonstrated little efficacy in various animal models of human disease. On the contrary, 1F11 showed efficacy in several models of inflammation yet was less potent at inhibiting chemotaxis in vitro with an IC50 of 21 nm Furthermore, we observed that 1B6 displayed a rapid dose-dependent clearance (t½ 10-60 h) in contrast to 1F11, which presented a dose-proportional pharmacokinetic profile and a half-life of 12 days. Moreover, 1B6 recognized glycosaminoglycan (GAG)-bound CXCL10, resulting in target-mediated clearance, which was corroborated using CXCL10-deficient mice. In contrast to 1B6, 1F11 inhibited the interaction of CXCL10 with GAGs, did not recognize GAG-bound CXCL10, and did not display target-mediated drug disposition. Confirming previous animal studies, 1B6 was poor at reversing glycemia in a model of type 1 diabetes, whereas 1F11 induced early and prolonged control of diabetes. Furthermore, when using 1A4, a subsequently generated anti-mCXCL10 mAb that shares the property with 1F11 of being unable to recognize CXCL10 immobilized on GAG, we observed a similar superior control of diabetes as compared with 1B6. We therefore concluded that targeting chemokines with antibodies such as 1B6 that recognize the more abundant GAG-bound form of the chemokine may not be the optimal strategy to achieve disease control.

Selective Blockade of the Ubiquitous Checkpoint Receptor CD47 Is Enabled by Dual-Targeting Bispecific Antibodies.

CD47 is a ubiquitously expressed immune checkpoint receptor that is often upregulated in cancer. CD47 interacts with its counter-receptor SIRPα on macrophages and other myeloid cells to inhibit cancer cell phagocytosis and drive immune evasion. To overcome tolerability and "antigen sink" issues arising from widespread CD47 expression, we generated dual-targeting bispecific antibodies that selectively block the CD47-SIRPα interaction on malignant cells expressing a specific tumor-associated antigen; e.g., CD19 or mesothelin. These bispecific κλ bodies are fully human, native IgG1 molecules, combining tumor targeting and selective CD47 blockade with immune activating mechanisms mediated by the Fc portion of the antibody. CD47-neutralizing κλ bodies efficiently kill cancer cells in vitro and in vivo but interact only weakly with healthy cells expressing physiological levels of CD47. Accordingly, a κλ body administered to non-human primates showed a typical IgG pharmacokinetic profile and was well tolerated. Importantly, κλ bodies preserve their tumoricidal capabilities in the presence of a CD47 antigen sink. Thus, dual-targeting κλ bodies allow for efficacious yet safe targeting of CD47 in cancer. Such a bispecific design could be applied to limit the extent of neutralization of other ubiquitously expressed therapeutic targets.

The antiviral restriction factor IFN-induced transmembrane protein 3 prevents cytokine-driven CMV pathogenesis.

The antiviral restriction factor IFN-induced transmembrane protein 3 (IFITM3) inhibits cell entry of a number of viruses, and genetic diversity within IFITM3 determines susceptibility to viral disease in humans. Here, we used the murine CMV (MCMV) model of infection to determine that IFITM3 limits herpesvirus-associated pathogenesis without directly preventing virus replication. Instead, IFITM3 promoted antiviral cellular immunity through the restriction of virus-induced lymphopenia, apoptosis-independent NK cell death, and loss of T cells. Viral disease in Ifitm3-/- mice was accompanied by elevated production of cytokines, most notably IL-6. IFITM3 inhibited IL-6 production by myeloid cells in response to replicating and nonreplicating virus as well as following stimulation with the TLR ligands Poly(I:C) and CpG. Although IL-6 promoted virus-specific T cell responses, uncontrolled IL-6 expression in Ifitm3-/- mice triggered the loss of NK cells and subsequently impaired control of MCMV replication. Thus, IFITM3 represents a checkpoint regulator of antiviral immunity that controls cytokine production to restrict viral pathogenesis. These data suggest the utility of cytokine-targeting strategies in the treatment of virus-infected individuals with impaired IFITM3 activity.

Use of a mouse model to identify a blood biomarker for IFNγ activity in pediatric secondary hemophagocytic lymphohistiocytosis.

Life-threatening cytokine release syndromes include primary (p) and secondary (s) forms of hemophagocytic lymphohistiocytosis (HLH). Below detection in healthy individuals, interferon γ (IFNγ) levels are elevated to measurable concentrations in these afflictions suggesting a central role for this cytokine in the development and maintenance of HLH. Mimicking an infection-driven model of sHLH in mice, we observed that the tissue-derived levels of IFNγ are actually 500- to 2000-fold higher than those measured in the blood. To identify a blood biomarker, we postulated that the IFNγ gene products, CXCL9 and CXCL10 would correlate with disease parameters in the mouse model. To translate this into a disease relevant biomarker, we investigated whether CXCL9 and CXCL10 levels correlated with disease activity in pediatric sHLH patients. Our data demonstrate that disease control in mice correlates with neutralization of IFNγ activity in tissues and that the 2 chemokines serve as serum biomarkers to reflect disease status. Importantly, CXCL9 and CXCL10 levels in pediatric sHLH were shown to correlate with key disease parameters and severity in these patients. Thus, the translatability of the IFNγ-biomarker correlates from mouse to human, advocating the use of serum CXCL9 or CXCL10 as a means to monitor total IFNγ activity in patients with sHLH.

Novel Insights into Interleukin 6 (IL-6) Cis- and Trans-signaling Pathways by Differentially Manipulating the Assembly of the IL-6 Signaling Complex.

The IL-6 signaling complex is described as a hexamer, formed by the association of two IL-6·IL-6 receptor (IL-6R)·gp130 trimers, with gp130 being the signal transducer inducing cis- and trans-mediated signaling via a membrane-bound or soluble form of the IL-6R, respectively. 25F10 is an anti-mouse IL-6R mAb that binds to both membrane-bound IL-6R and soluble IL-6R with the unique property of specifically inhibiting trans-mediated signaling events. In this study, epitope mapping revealed that 25F10 interacts at site IIb of IL-6R but allows the binding of IL-6 to the IL-6R and the recruitment of gp130, forming a trimer complex. Binding of 25F10 to IL-6R prevented the formation of the hexameric complex obligate for trans-mediated signaling, suggesting that the cis- and trans-modes of IL-6 signaling adopt different mechanisms for receptor complex assembly. To study this phenomenon also in the human system, we developed NI-1201, a mAb that targets, in the human IL-6R sequence, the epitope recognized by 25F10 for mice. Interestingly, NI-1201, however, did not selectively inhibit human IL-6 trans-signaling, although both mAbs produced beneficial outcomes in conditions of exacerbated IL-6 as compared with a site I-directed mAb. These findings shed light on the complexity of IL-6 signaling. First, triggering cis- versus trans-mediated IL-6 signaling occurs via distinctive mechanisms for receptor complex assembly in mice. Second, the formation of the receptor complex leading to cis- and trans-signaling biology in mice and humans is different, and this should be taken into account when developing strategies to inhibit IL-6 clinically.

Exploiting light chains for the scalable generation and platform purification of native human bispecific IgG.

Bispecific antibodies enable unique therapeutic approaches but it remains a challenge to produce them at the industrial scale, and the modifications introduced to achieve bispecificity often have an impact on stability and risk of immunogenicity. Here we describe a fully human bispecific IgG devoid of any modification, which can be produced at the industrial scale, using a platform process. This format, referred to as a κλ-body, is assembled by co-expressing one heavy chain and two different light chains, one κ and one λ. Using ten different targets, we demonstrate that light chains can play a dominant role in mediating specificity and high affinity. The κλ-bodies support multiple modes of action, and their stability and pharmacokinetic properties are indistinguishable from therapeutic antibodies. Thus, the κλ-body represents a unique, fully human format that exploits light-chain variable domains for antigen binding and light-chain constant domains for robust downstream processing, to realize the potential of bispecific antibodies.